1. Technical Field
The present invention relates to a piezoelectric element which includes a first electrode, a piezoelectric layer, and a second electrode, a liquid ejecting head which includes the piezoelectric element, and a piezoelectric element device which includes the piezoelectric element.
2. Related Art
A liquid ejecting head in which a piezoelectric element is deformed to cause pressure to fluctuate in a liquid in a pressure generation chamber and thus causing droplets to be ejected from a nozzle opening which communicates with the pressure generation chamber is known. As a representative example of the liquid ejecting head, there is an ink jet type recording head that ejects an ink droplet as a droplet.
The ink jet type recording head includes, for example, a piezoelectric element on one surface side of a flow passage formation substrate in which a pressure generation chamber communicating with a nozzle opening is provided. A vibrating plate is deformed by driving the piezoelectric element, and thus pressure on an ink in the pressure generation chamber is changed, and an ink droplet is ejected from the nozzle opening.
In such a piezoelectric element, a structure is proposed in which the strength of a so-called arm which is a portion of a vibrating plate supporting a piezoelectric element when the piezoelectric element deforms the vibrating plate is improved (for example, see JP-A-2000-52550). Specifically, a beam portion is provided at a portion of the arm, the thickness of which is reduced in order to increase the displacement of the vibrating plate, and thus an improvement in strength is achieved.
However, forming a beam portion in the vicinity of an end portion of the piezoelectric element is not possible or is difficult. Thus, efficiently suppressing the piezoelectric element from being fractured by the stress concentration on the end portion may not be possible. Stress may be concentrated in the vicinity of an end portion at a non-active portion of the piezoelectric element, and thus the piezoelectric element may be fractured.
Such a problem is not limited to a piezoelectric element used in a liquid ejecting head such as an ink jet type recording head, and similarly occurs in a piezoelectric element used in other types of devices.